Mark Threlfall: Power meters have been on the scene for over 30 years now, yet
for a very long time they're at all almost solely used by pro riders. The data that they
produced just seemed far too specific and complicated for many people to understand
and the cost put a lot of people off for a very long time. Fast forward to today and boy, have
things changed. The awareness of how invaluable this parameter data is has grown immensely.
The data itself is just better understood now and more easily accessible,
and you don't necessarily need a second mortgage to buy one of these these days. There is so many
options out there in terms of power meters. Today, I'm going to run through
a number of those for you so that you have a better idea when you go to get one.
[music] Let's start with a bit of history.
The most obvious place to measure power is where the physiological effort to create that power is
first being generated. That is obviously our legs. Although unfortunately, we can't simply
plug into our legs and just measure power from that easily, anyway. The next port of call was
to measure where the power was first being put into the bike and the torque being generated.
In 1986, SRM essentially became the trailblazers in power meter measurement for cycling,
as they set out to measure power from the crankset spider region on the bike. This solution made the
most sense because there is space there to store strain gauges, batteries and also it's just a good
well-protected area. However, as times moved on more and more options have become available
for alternative power meter designs. After all, power travels through various
areas of the bike, we've got the rear hub, the pedals, the cranks, the chainrings, even
the bottom bracket and they all come with their own advantages and disadvantages. Nonetheless,
we now have far more options today. It's grown from just simply that one from SRM, originally,
up to well over 20 brands today. [music]
Another consideration with any power meter is, of course, the weight penalty. With Quarq,
for instance, with their crank-based, spider-based power meter, it only adds an additional 140 grams
to the system, which is pretty impressive, and also with an excellent battery life of over
2,000 hours of ride time. Flipping back to the beginning, we were talking about SRM. They're
pretty much still the gold standard in terms of crank-based, spider-based power meters. They're in
their seventh or eighth iteration of that design but they do come at a pretty eye-watering cost,
significantly more than, say, Quarq, which you can pick up for under £700 or £600 in some cases.
In terms of Quarq, you can set them up however you like and buy the relevant power meter for
your system. If you've got Shimano or SRAM, you can set them up to match that. Of course,
if you have got Shimano on your bike and you want to fully commit to that, you can go down
the Dura-Ace Di2 power meter option, which you can pick up for around £1,000 or just under that.
Obviously, one of the big disadvantages of a crank-based power meter,
although they are relatively durable and reliable once set up, is the fact that you
can't easily flip them or switch them from bike to bike should you want to. Talking of ease of
use and winding the clock back a number of years now, one of the most popular alternatives to the
crank-based power meter was the rear hub-based power meter, and PowerTap jumps to mind here.
According to engineers, this was possibly one of the most accurate and reliable locations
for putting a power meter on the bike, although unfortunately,
it does have a few drawbacks and disadvantages. Firstly,
the weight addition. Typically they would add around 300 grams, if not more in some cases. Also,
not all wheel manufacturers would make wheels that were compatible with these hubs.
Because I have used one myself, one of the biggest issues was actually just
the ease of transferring one of these hubs from your training wheels over to a
set of race wheels. Unfortunately, for those very reasons, they're a pretty rare sight these days.
[music] When it comes to
ease of fitting and simplicity, pedals have been a bit of a game-changer, really, in the power meter
measurement world. Garmin kind of opened up the market here with their Vectors a number of years
back. They can be fitted to any cranks, they can be switched between bikes quickly and easily,
and they offer dual-sided measurement, both left and right. Garmin are in their third iteration of
the Vector pedals now, with both the single-sided and dual-sided options. The single-sided
coming almost half the price of the dual-sided. There are so many more options out there now from
numerous other brands. We've got the Assioma pedals, which have come out more recently, an
incredibly popular option due to their relatively reasonable price and low weight. We've also got
the PowerTap pedals, but also this collaboration between Look and SRM with their Exact pedals. They
come in at the higher price point, but, obviously, with the accuracy from the SRM strain gauges.
There are some disadvantages to the pedals. They are quite exposed, so there is the ability to
knock them and that, therefore, does sometimes come with some reliability issues. There is the
limitation in terms of the cleats that you can use with them, with pretty much
all of them using Look cleats. [music]
We're now moving on and although not quite as simple as literally just switching pedals from
bike to bike, we do have another relatively straightforward option, providing you have
the right tools, and that is a crank-based power meter. Stages jumped in and filled this market a
number of years ago with their non-drive side, single-sided, crank-based power meter option.
One of the beauties of this was that you could literally pick up a crank for pretty
much any system. You could get it for Shimano, SRAM, Campagnolo, Cannondale, Rans Designs,
Specialized, you name it, you are sorted. With it being a single-sided power meter, it came at
a far lower cost which is very attractive for many people. That, obviously, comes with
its disadvantages and the fact that it is only single-sided, so it has to extrapolate the data
and the power produced on that side and give you an overall power read, so not quite as accurate.
However, that only added an additional 20 grams to that crank. That said, 4i have jumped in with
something even lighter again, adding only nine grams and also the option to adjust
the power settings for any leg imbalances that you know of. Stages have also actually updated
with a dual-sided power meter. There really are a number of options out there in terms
of a crank-based team. [music]
I've got one final consideration for you, and this one's a little bit different. It comes from Rotor
with their INpower power meter. This one actually stores all the power meter electronics and battery
within the spindle of the crankset, so it's all hidden away. From experience, this makes it a very
robust system, and also an incredibly accurate system. Also, a remarkable battery lifetime on
it. From charge, it has around 250 hours. The only drawback with this is bottom brackets, which I'm
sure many people have experienced before. Yes, you can get some issues with those
but that said Rotor have done a very good job in making sure that it's well designed
and adapts so that it's compatible with pretty much all bottom brackets out there.
There we go, a lot of options I've mentioned there. I haven't deep-dived into any particularly,
so if you do have any questions please do drop them in the comments section down below.
I have given you a pretty broad overview of most out there. I may have missed off some examples,
so again, don't shoot me down for that. I hope you have enjoyed today's video. If so,
please do give it a like, and don't forget to give us a follow over on social media and
subscribe just down below. [00:08:33] [END OF AUDIO]